제출 #870788

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
870788		Turkhuu	Building Bridges (CEOI17_building)	C++17	100 / 100	51 ms	9044 KiB

building

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const ll inf = 1e18;
ll s(int x) {
    return (ll)x * x;
}
struct Line {
	mutable ll k, m, p;
	bool operator<(const Line& o) const { return k < o.k; }
	bool operator<(ll x) const { return p < x; }
};

struct LineContainer : multiset<Line, less<>> {
	// (for doubles, use inf = 1/.0, div(a,b) = a/b)
	static const ll inf = LLONG_MAX;
	ll div(ll a, ll b) { // floored division
		return a / b - ((a ^ b) < 0 && a % b); }
	bool isect(iterator x, iterator y) {
		if (y == end()) return x->p = inf, 0;
		if (x->k == y->k) x->p = x->m > y->m ? inf : -inf;
		else x->p = div(y->m - x->m, x->k - y->k);
		return x->p >= y->p;
	}
	void add(ll k, ll m) {
		auto z = insert({k, m, 0}), y = z++, x = y;
		while (isect(y, z)) z = erase(z);
		if (x != begin() && isect(--x, y)) isect(x, y = erase(y));
		while ((y = x) != begin() && (--x)->p >= y->p)
			isect(x, erase(y));
	}
	ll query(ll x) {
		assert(!empty());
		auto l = *lower_bound(x);
		return l.k * x + l.m;
	}
};
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int n;
    cin >> n;
    vector<int> h(n), w(n);
    for (int &i : h) cin >> i;
    for (int &i : w) cin >> i;
    vector<ll> dp(n);
    dp[0] = -w[0];
    LineContainer a;
    a.add(2 * h[0], -1LL * h[0] * h[0] - dp[0]);
    for (int i = 1; i < n; i++) {
        a.add(2 * h[i], -1LL * h[i] * h[i] - (dp[i] = 1LL * h[i] * h[i] - w[i] - a.query(h[i])));
    }
    ll ans = dp[n - 1];
    for (int i : w) ans += i;
    cout << ans;
    return 6/22;
}

• Subtask 1: 30 / 30
• Subtask 2: 30 / 30
• Subtask 3: 40 / 40